cylc-7.8.0 is likely to be the final cylc-7.x release, aside apart from a few 7.8.x maintenance releases if required.
The development team is currently gearing up for the next major release, cylc-8, for which we will port Cylc to Python 3 and replace the aging PyGTK desktop GUIs with modern web GUIs. We expect early beta versions of the new system to be available for testing by mid 2019.
For those interested, some documentation of cylc-8 plans - including the Agenda for a development workshop to be held in Australia next week - can be found here:
https://cylc.github.io/cylc-admin/
Regards,
Hilary